05-19-2013, 08:02 PM
Hi there, According to the Microsoft whitepaper the following specs are defined for the Excel password security encryption:
Key derivation is performed using 50,000 iterations[source] of SHA-1 (increased to 100k in SP2).
Uses a 16-byte (128-bit) random salt.
AES is the block cipher used to encrypt the document.
By default, 128-bit key are used. There is a registry tweak to change this to 256-bit.
The AES block cipher is implemented in Microsoft's CSP / CryptoAPI.
This info give me a good point to crack a Excel password, but... I don't find any information or documentation to get the hash from an Excel file.
Anyone knows how get it?
Thanks in advance and sorry for my english
Byebye!
Key derivation is performed using 50,000 iterations[source] of SHA-1 (increased to 100k in SP2).
Uses a 16-byte (128-bit) random salt.
AES is the block cipher used to encrypt the document.
By default, 128-bit key are used. There is a registry tweak to change this to 256-bit.
The AES block cipher is implemented in Microsoft's CSP / CryptoAPI.
This info give me a good point to crack a Excel password, but... I don't find any information or documentation to get the hash from an Excel file.
Anyone knows how get it?
Thanks in advance and sorry for my english
Byebye!